Oil contamination can significantly speed up the deterioration of a lubricating system or equipment, in addition to being the source and cause of breakdowns and malfunctions in industrial machinery.
Keeping oil dirt levels under control is a fundamental and recurring task, which involves constant vigilance, since, regardless of the sector or type of machinery in which it operates, contamination is an inherent part of the operation of the oil at any stage of its life cycle.
This is because, in a lubrication system, the oil’s job consists of being placed between two mechanical elements to prevent them from coming in direct contact with each other, thus reducing the friction, heating, oxidation, deterioration or possible breakage of these elements.
But to do so, it must also fulfill the important function of keeping the lubrication areas clean, protecting them from the particles that are generated by the operation of the machine itself.
The oil removes impurities, but it also drags and transports them to the filtering systems, a process during which the particles enter into circulation throughout the system and can cause the deterioration of the components to be sped up.
In addition to the dirt associated with the operation of the machine, lubricating oil often has to coexist with other types of agents that are externally incorporated into the system. In this sense, some industrial sectors are particularly sensitive to processes that are external to the oil’s own operation, and that can add contaminants to the lubricant.
1. Wind
In the wind industry, it is common for the lubrication fluid to become contaminated when refilling or changing the oil with a reference that is different to the lubricant already present in the machine. In this regard, it should be noted that two oils of different references may produce an unexpected reaction, even if both can be used in that equipment, due to their different physicochemical characteristics. This incompatibility can lead to different problems such as deposits and sludge and can cause serious malfunctions in the machinery.
The location where the wind turbines are installed can make it more likely for there to be contamination produced by environmental particles. The location of these devices, which are necessarily out in the field, causes them to be more exposed to external agents.
In the case of offshore wind farms, in addition to the most common causes of contamination, the oil can also be affected by seawater, leading into possible corrosion. In equipment that is installed in other hostile locations, such as desertic zones, it is common for dust particles to end up making their way into the systems.
2. Mining and public-works equipment
Mining and public-works equipment have the same exposure to external agents as the wind industry, but there is another source of added contamination that comes from the automotive elements. In these two industries, the engines operate in highly aggressive environments and the soot that is inherently generated through the operation of the machine is joined by dust particles from the environment.
In these sectors, silicon and soot particles are the main causes of contamination, but they are not the only ones. The oil can also be affected by fluids such as water or coolants, especially glycol. Mining and public-works equipment are characterized for being high-power, driven by large engines that require cooling systems of equal size. The coming together between the size of the glycol deposits and the hostile environment in which they are located increases the likelihood of a leakage in the lubricant, either due to intense use or because of damage from external impacts.
3. Automotive
The production processes in the automotive industry are carried out in cleaner environments, meaning the main source of lubricant contamination is internal. This is the case of robots where, depending on the plant design, there can be a total of thousands of units, with 2 to 3 elbow joints, lubricated by oil in each machine. For these devices, contamination can become a highly critical problem, as the variation of allowed viscosity (or the number of contaminating particles that they can tolerate depending on the operation) is very low, a typical characteristic of highly-precise work environments. The use of a contaminated oil can lead to errors in the positioning of the robot. If the contamination alters the movement of the robot, no matter how slight the deviation is, the production process may come to a halt.
In spite of the cleaner environment, one of the elements that make up the assembly lines in the automotive industry is more likely to receive external contaminants due to its design: the press. These devices have an open circuit and, at times during the process, the oil is exposed to the environment and to any of the particles that are possibly suspended in the air. These particles can speed up the deterioration of these systems.
4. Generation of conventional energy
For the generation of conventional energy, there are two important elements that are susceptible to contamination in the lubricating oil: gas and steam turbines.
In steam turbines, the inherent contaminant is water, in other words, the water that is produced by the steam generation process itself. The lubricant can pick up part of that steam, which transforms into water and passes into the system.
Gas turbines are very clean systems, in which the presence of external agents is very uncommon. Here, the most common source of contamination in the lubricant is the presence of wear particles.
In both machines, the lubricating fluid has restrictive cleaning requirements, and it is always essential for these parameters to be controlled in order for the machine to operate correctly.
